Influence of Compression Ratio on Pressure in the Cylinder of Internal Combustion Engine

Currently, variable compression ratio engines are not used, presumably due to the complexity of the design. Currently, various engines are being developed that differ in design, kinematics, load control and compression ratio changes. The article presents the results of calculating the efficiency and fuel consumption for a crankshaft with a rotation speed of 2000 and 4000 rpm with a compression ratio of 8.6 and a rotation speed of 4000 rpm with a compression ratio of 13 and provides combustion characteristics m = 3 and 1. It is shown that these characteristics at higher speeds they approach the indicators at lower speeds with an increase in the compression ratio. The engine parameters were calculated for various modes based on Wiebe theory. Based on the calculations, the efficiency and fuel consumption are determined for the corresponding modes and the nature of the engine operation. It has been found that with an increase in the crankshaft rotation speed, the cycle efficiency will decrease by almost half and fuel consumption will increase accordingly; with an increase in the compression ratio, the efficiency is restored and fuel consumption decreases accordingly.